Fuel cell and fuel cell stack

Abstract

In a solid polymer electrolyte membrane [film] type fuel cell of the invention, where a pair of electrodes are provided on opposite sides of a solid polymer electrolyte membrane [film], and the outside thereof is clamped by a pair of separators, and nonconductive picture frame-shaped members 61 are arranged at the outer edge portions of the separators, for allowing increase and decrease of a space between separators, while sealing a gap between the separators.

What is claimed is: 
     
       1. A fuel cell stack formed by stacking a plurality of fuel cells comprising:
 a first fuel cell; and 
 a second fuel cell adjacent to the first fuel cell, 
 wherein each of the first fuel cell and the second fuel cell includes:
 an electrode membrane assembly formed by a pair of electrodes sandwiching a solid polymer electrolyte membrane, 
 a first separator and a second separator sandwiching outsides of the pair of electrodes, wherein each separator includes a plurality of communication holes, the plurality of communication holes including reactant gas communication holes and cooling medium communication holes, and 
 insulating members provided around the plurality of communication holes; 
 
 wherein a first space is formed between the insulating members formed on the first separator and the insulating members formed on the second separator, or 
 wherein a second space is formed between the insulating members formed on the first separator of the first fuel cell and the insulating members formed on the second separator of the second fuel cell adjacent to the first separator of the first fuel cell, when the first fuel cell and the second fuel cell are stacked in a stacking direction. 
 
     
     
       2. A fuel cell stack according to  claim 1 , wherein the insulating members of the first separator of the first fuel cell and the insulating members of the second separator of the second fuel cell are formed such that the first separator of the first fuel cell and the second separator of the second fuel cell are capable of relatively sliding so as to allow increase and decrease of the second space while said insulating members are sealing the second space. 
     
     
       3. A fuel cell stack according to  claim 2 , wherein said insulating members are made of an elastic material. 
     
     
       4. A fuel cell stack according to  claim 3 , wherein inner peripheral surfaces of the plurality of communication holes are covered by the insulating members. 
     
     
       5. A fuel cell stack according to  claim 4 , wherein one of the insulating members of the first separator of the first fuel cell is formed in a flat shape, and another one of the insulating members of the second separator of the second fuel cell facing to said one of the flat insulating member is formed in a protruded shape. 
     
     
       6. A fuel cell stack according to  claim 5 , wherein each separator further includes a reaction surface, the fuel cell stack further comprising:
 reaction surface peripheral sealing members surrounding the reaction surfaces of said first and second separators, 
 wherein one of the reaction surface peripheral sealing members of the first separator of the first fuel cell is formed in a flat shape, while another one of the reaction surface peripheral sealing members of the second separator of the second fuel cell facing said flat reaction surface peripheral member is formed in a protruded shape. 
 
     
     
       7. A fuel cell stack according to  claim 6 , wherein one of the insulating members formed on the first separator of the first fuel cell or one of the insulating members formed on the second separator of the second fuel cell extends to entirely cover an outside portion of said reaction surface peripheral sealing member of the first separator of the first fuel cell or the second separator of the second fuel cell, respectively. 
     
     
       8. A fuel cell stack according to  claim 7 , wherein on the first separator of the first fuel cell or on the second separator of the second fuel cell, said reaction surface peripheral sealing member and said insulating member are integrally formed. 
     
     
       9. A fuel cell stack according to  claim 8 , wherein on the first separator of the first fuel cell or on the second separator of the second fuel cell, both outside surfaces of said reaction surface peripheral sealing member are entirely covered by the insulating member which is integrally formed with said reaction surface peripheral sealing member.